Conveyor belt cleaning system

ABSTRACT

An assembly and method for cleaning a conveyor belt system is disclosed. The cleaning assembly is for removing liquids and solids from an endless conveyor belt, the assembly includes a plurality of laterally extending liquid absorbent material sheets disposed adjacent the belt, with the sheets collectively defining a contact face that is engageable with the belt for wiping liquids from the belt.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation-in-part of application Ser. No.10/309,790, filed Dec. 4, 2002, which is hereby incorporated byreference in its entirety.

BACKGROUND OF THE INVENTION

The present invention is directed to a system for cleaning conveyorbelts, and particularly to a cleaning assembly for dual conveyor beltsystems.

A conveyor system employing an endless belt may, over time, requirecleaning of the belt surface. This is particularly true when the belt isused for conveying an article during processing of the article whereportions of the article, in one form or another, are transformed. Suchtransformations may be accomplished by, for example, applying pressureor heat to the article being conveyed.

One form of such a conveying system employs two endless belts. Each belttraverses a separate belt travel path, with the two belt travel pathstogether defining an article transport path between opposed faces of thebelts. The article being conveyed, upon entry into the article transportpath, is simultaneously engaged by the opposed faces of the two belts asit moves along an article processing path. One specific example of sucha process is a cooking process, where the article being conveyed is afood item which is cooked while simultaneously being conveyed by theconveyor belt system. In an article cooking application, heat may beapplied to the article as it is conveyed by the two belts along thearticle transport path defined by the belts.

As the article is heated, fluids in the article may leave the article inliquid form (i.e., water or oils) or in gas form (i.e., steam or vapor).In addition, portions of the article may separate from the articleduring processing, causing debris to remain on the belt once the articlehas left the article transport path. As the endless belts operate overtime to transport a plurality of articles, the build up of liquids anddebris on the belts can become significant, affecting the performance ofthe belts in processing the article. In addition, the migration offluids and/or debris into the operating equipment for the belts andother associated processing equipment can degrade the performance ofsuch equipment. Therefore, it is desirable that any debris or excessliquids created on the belt during processing be removed from the beltin an efficient and expeditious manner.

BRIEF SUMMARY OF THE INVENTION

In one embodiment, the present invention is an assembly for removingliquids and solids from an endless conveyor belt. The assembly includesa plurality of laterally extending liquid absorbent material sheetsdisposed adjacent the belt, with the sheets collectively defining acontact face that is engageable with the belt for wiping liquids fromthe belt.

In another embodiment, the cleaning assembly includes a liquid absorbentmaterial unit disposed adjacent the belt. The absorbent material unitcomprises a stack of laterally extending sheets of absorbent materialaffixed together at first edges of each of the sheets, and at oppositesecond edges the sheets collectively define a contact face on theabsorbent material unit that is engageable with the belt for wipingliquids and solids from the belt. Also, at least one of the sheetsdeflects when engaged with the belt.

In another embodiment, the present invention is a method for removingliquids and solids from an endless conveyor belt. The method includesadvancing the belt, and engaging the belt with a contact face of aliquid absorbent material unit disposed adjacent the belt. The absorbentmaterial unit comprises a stack of laterally extending sheets ofabsorbent material affixed together at first edges of each of thesheets, and at opposite second edges the sheets collectively define thecontact face of the absorbent material unit. At least one of the sheetsdeflects when engaged with the belt.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further explained with reference to thedrawing figures listed below, wherein like structures are referred to bylike numerals throughout the several views.

FIG. 1 is a schematic illustration of a conveyor belt system having theinventive cleaning assembly thereon.

FIG. 1A is a sectional view as taken along lines 1A-1A in FIG. 1,showing a pair of belt seals between opposed faces of the belts along anarticle transport path defined by and between the belts.

FIG. 2 is a plan view, as viewed from the article conveying belt face,of a belt cleaning blade assembly of the present invention.

FIG. 3 is a view of the blade of FIG. 2, as viewed from the downstreamside of the belt.

FIG. 4 is a perspective view of the blade of FIG. 2.

FIG. 5 is a sectional view, as taken along lines 5-5 in FIG. 2.

FIG. 6 is a perspective view of the blade of FIG. 2, and its associatedfilter and liquid collector.

FIG. 7 is a perspective view of an exemplary absorbent material padwhich is disposed for contact with the belt face downstream from thewiper blade.

FIG. 8 is a perspective view of the absorbent material pad disposed in apad holding housing, having a pad exposing window therein.

FIG. 9 is a sectional view through the housing of FIG. 7, schematicallyshowing an alternative motor and/or liquid collection system connectedthereto.

FIG. 9A is an enlarged longitudinal section through an absorbentmaterial pad cartridge and its associated belt, aligned for engagementand operation.

FIG. 10 is a perspective view of an alternative embodiment of the beltcleaning absorbent material pad of the present invention.

FIG. 11 is a schematic illustration of a conveyor belt system havinganother alternative embodiment of the inventive cleaning assemblythereon.

FIG. 12 is a perspective view of another alternative embodiment theabsorbent material pad unit of the present invention.

FIG. 13 is an enlarged longitudinal section through the absorbentmaterial pad unit of FIG. 12 and its associated belt, aligned forengagement and operation.

FIG. 14 is a schematic illustration of an absorbent material pad alignedat a tilted angle relative to the belt engaged by the absorbent materialpad.

FIG. 15 is an enlarged view of the portion of FIG. 1A indicated by thedashed outline 11, showing one of the belt seals.

FIG. 16 is a perspective view of a portion of an alternative design forthe belt seal.

FIG. 17 is a partial sectional view showing the belt seal of FIG. 16disposed between the opposed faces of the belts.

FIG. 18 is a perspective view of a portion of an alternative designedfor the belt seal.

FIG. 19 is a partial sectional view showing the belt seal of FIG. 14disposed between the opposed faces of the belts.

While the above-identified drawing figures set forth several embodimentsof the invention, other embodiments are also contemplated, as noted inthe discussion. In all cases, this disclosure presents the presentinvention by way of representation and not limitation. It should beunderstood that numerous other modifications and embodiments can bedevised by those skilled in the art which fall within the spirit andscope of the principles of this invention.

DETAILED DESCRIPTION

FIG. 1 illustrates an article conveying system 20 including the cleaningassembly components of the present invention. The conveying system 20has first and second endless belts 22 and 24. Each belt is supported bya plurality of rollers such as rollers 26 for belt 22 and rollers 28 forbelt 24. The rollers define a separate belt travel path for each belt,and at least one of the rollers 26 and 28 for each belt is driven tomove that belt along its respective belt travel path. Arrows 30 indicatethe direction of movement of belt 22, while arrows 32 indicate thedirection of movement of belt 24. Typically, the belts are driven tomove at the same rate, although not necessarily.

Each belt has a top face for engaging an article being conveyed by thebelt, and an opposite bottom face for engaging its respective rollers.Accordingly, first belt 22 has a top face 34 and a bottom face 36, andsecond belt 24 has a top face 38 and a bottom face 40.

The first and second endless belts 22 and 24 together define an articletransport path 45 between opposed top faces 34 and 38 of the belts 22and 24, respectively. The article transport path 45 generally consistsof the space between the opposed top faces of the belts (see space “d”in FIG. 1A), and extends longitudinally for so long as the top faces areopposed, and extends laterally to adjacent the lateral side edges of thebelts. An article to be conveyed, such as article 46 a, is introduced ata first end of the article transport path 45, is carried between theopposed top faces of the belts (as indicated by articles 46 b, 46 c and46 d illustrated in phantom in FIG. 1) and exits the article transportpath 45 adjacent a second end thereof (as illustrated by processedarticle 46 e). The article transport path 45 may be linear, asillustrated in FIG. 1, or may include one or more curves, asnecessitated by the particular processing being conducted. In addition,the spacing “d” across the article transport path between opposed topfaces of the belts may vary. For instance, the article transport pathmay be wider in spacing adjacent its first end than adjacent its secondend. In the illustrated embodiment, the article transport path 45 is agenerally upright transport path, with its first end higher than itssecond end.

In some applications (e.g., cooking), it may be desired to present aheated conveying surface to the article 46. In that situation, heatingelements, such as heater 48 and 50 may be provided to heat the first andsecond belts 22 and 24 along the article transport path 45.

The endless belts 22 and 24 may be formed from a material that has thesufficient flexibility to traverse its belt travel path and has otherdesired characteristics, such as a particular frictional characteristicrelative to the article being transported and its respective supportrollers, and if heating is to be applied to the article, desired thermalcharacteristics. In one embodiment, the belt may be constructed from anickel iron alloy known as Invar™ available from Imphy S.A. Corp.,Paris, France. The faces of the belt may also be coated with desiredmaterials, either to control frictional, thermal or othercharacteristics. Examples of coatings for the top face of the belt arethe Excalibur™ coating available from Whitford Corporation, WestChester, Pa. and the Teflon™ coating available from E.I. du Pont deNemours and Company, Wilmington, Del. While FIG. 1 illustrates heatingthe article as it traverses the article transport path 45, othermanipulation or treatment of the article is also possible, including,for example, the application of pressure and/or the introduction ofother components onto the article (e.g., coatings, flavorings, etc.)

During use, debris and liquid may be deposited on the top faces 34 and38 of the belts 22 and 24. Such debris typically comes from the articlebeing processed, either in the form of article breakage or theextraction of liquids or gases therefrom during processing. The presenceof debris and excess liquids on the belts 22 and 24 can degradeperformance of the conveying system 20 by, for example, adverselyaffecting the frictional and/or thermal properties of the belt withrespect to the article being transported. In addition, such debris andliquids may also interfere with the engagement of a belt and itsrespective support rollers, and with other associated processingequipment. Conveying systems such as those illustrated in FIG. 1 aretypically employed in highly automated and high product throughputprocessing systems. Accordingly, extensive downtime of the system forthe purpose of cleaning the belts is unacceptable. Such downtime notonly inhibits the production of processed articles, but also may berather labor intensive. Additional handling of the system componentsalso may increase the possibility of damage to the belt, its associatedrollers and other equipment components during cleaning and/or removal ofa belt for cleaning.

The present invention provides a belt cleaning system which effectivelycleans the belt during conveying operations, thereby avoiding thenecessity for a system shutdown of undesirable duration for beltcleaning. The inventive system may include a belt wiping blade,absorbent belt wiping pad and belt edge containment seals. Thesecomponents capture debris and liquids on the top face of each belt,remove it from the belt and/or direct it away from the edges and bottomface of the belt (where it could come into engagement with the supportrollers and other equipment (e.g., heaters)).

Belt Wiping Blade Assembly

A belt wiping blade assembly 60 is illustrated in cooperation with thesecond belt 24 in FIG. 1. The belt wiping blade assembly 60 includes ablade 62 engaging and extending across the top face 38 of the secondbelt 24. Opposite the blade 62, the belt 24 is supported relative to theblade 62 by one of the rollers 28. The blade 62 is held in place bysuitable structure (not shown) which may include means for selectivelymoving the blade 62 toward and away from the belt 24. The blade 62 isdisposed adjacent a lowest extent of the travel path of the belt 24, andin one embodiment, is disposed slightly upstream from that lowestextent, which causes the waste and debris engaged by the blade 62 to beremoved from the belt 24 before its natural drop point.

The shape of the blade 62 in one embodiment is illustrated more fully inFIGS. 2-6. FIG. 2 illustrates the blade in plan view, as viewed from thetop face 38 of the belt 24 engaging the blade 62. In FIG. 2, lateralside edges 64 and 66 of the belt 24 are illustrated in phantom. Theblade 62 has an elongated central section 68 and lateral end edges 70and 72. Each end edge has a diversion ramp 74, 76, respectively,projecting upstream relative to belt movement past the blade 62. Eachdiversion ramp 74 and 76 extends outwardly from the central section 68of the blade 62 at an obtuse angle. An upper edge of the blade may beconfigured to accommodate the belt face it engages. For instance, eachof the diversion ramps 74 and 76 may have an arced surface adjacent anupper edge 78 of the blade, and/or a portion of the upper edge 78 of theelongated section 68 of the blade 62 may include a radius (see e.g.,radius portion 80 along the upper edge 78 of the blade 62). Accordingly,the blade 62 extends across the entire lateral width of the belt 24, andany debris and excess liquid disposed on the top face 38 of the belt 24is diverted off of the belt 24 by the blade 62. The diversion ramps 74and 76 serve to direct debris and liquids away from the lateral sideedges 64 and 66 of the belt 24.

In one embodiment, the blade is formed from a fluoroelastomer rubbersuch as Viton™ material available from E. I. du Pont de Nemours andCompany, Wilmington, Del. The blade is softer than the belt surfacewhich it engages so that the blade does not scratch the belt as the belttraverses its travel path past the stationary blade. The surfaces of theblade contacting the belt are smooth, the blade is generally stiff andresilient, and the blade does not absorb or exhibit an affinity for anyparticular form of liquid. In addition, it is important that the bladehave a melt temperature higher than the possible temperature of thebelt. In one embodiment, the blade has a melt temperature higher than350° F. (177° C.), preferably higher than 400° F. (204° C.), and morepreferably higher than 450° F. (232° C.).

In one embodiment, a belt wiping blade assembly is provided for each ofthe belts 22 and 24. The belt wiping blade assembly 60 described aboveis disclosed with respect to the second belt 24, while another beltwiping blade assembly 90 provided for the first belt 22, as seen inFIG. 1. The belt wiping blade assembly 90 has a blade 92, which in allregards is the same as the blade 62. The belt wiping blade assembliesare identically oriented with respect to their respective belts,although the orientations are mirror images of one another, as seen inFIG. 1.

In each belt wiping blade assembly, a filter or screen is disposed belowthe blade. Debris and liquid removed from the belt by the blade isdirected onto the filter. Liquid flows through the filter, while debrisis collected on and in the filter for disposal. The belt wiping bladeassembly 60 has a filter 94 disposed below the blade 62, while the beltwiping blade assembly 90 has a filter 96 disposed between the blade 92(see FIGS. 1 and 5). The filters 94 and 96 may be formed from a layer ofscrim material or nonwoven material, for example, with voids allowingliquid to flow through and a mat or sheet of fibers which stop the flowof debris and other particulate matter therethrough. For example, awoven fiberglass or polyester scrim or nonwoven polymeric fibers maysuffice as the filter. The filters 94 and 96 are supported by suitablestructure (not shown in FIGS. 1 and 5) under their respective blades 62and 92.

As the blade becomes soiled or damaged in use, it may be removed forcleaning or replacement independently of its respective filter.Alternatively, the blade and filter may be connected in cartridge form(as indicated schematically by phantom cartridge 98 in FIG. 5) for jointremoval (for cleaning or replacement) relative to their respective belt.FIG. 6 illustrates an embodiment wherein the filter 94 is laterallyslideably received in a housing 100, and has an endplate 102 connectedthereto for facilitating slideable removal of the filter 94 relative tothe housing 100, as indicated by arrows 104. The filter 94 is thusreplaceable without removal of the blade 62 thereabove.

A liquid collector is disposed under the filter of each belt wipingblade assembly to collect liquid removed from the top face of the beltby the blade and run through its filter. The liquid collector can be atrough, or a diverter tray with a drain and conduits leading to a liquidcollection reservoir at some remote location (not shown). FIG. 1illustrates the liquid collectors as troughs 106 and 108 of the beltwiping blade assembly 60 and 90, respectively. In FIG. 6, the trough 106for the belt wiping blade assembly 60 is shown with a sloped bottom 110,tilting downwardly from one lateral side edge of the belt 24 to theother side edge, with a drain conduit 112 at the lowest end of thesloped bottom 110. The liquid collectors 106 and 108 are supportedrelative to the respective belts, blades and filters by suitablestructure (not shown). If the liquid collector is not provided with adrain, it must be accessible and removable for cleaning and disposal ofany liquid therein.

Absorbent Pad Assembly

In spite of the fact that each belt has a blade wiping against it forliquid and debris removal, not all liquids and solids may be removedfrom a belt by its respective blade. Accordingly, an absorbent materialcan be brought into engagement with the top face of each belt downstreamfrom the blade for further removal of liquids and solids from the belt.The absorbent material urged into contact with the top face of the beltto wick off and further to wipe off liquids and solids borne by thebelt.

FIG. 7 illustrates an exemplary design for an absorbent pad 120. A core122 extending along a central axis 124 has a plurality of lobes 126 ofabsorbent material 128 affixed thereto so that the lobes 126 radiateoutwardly therefrom. Outer edges 129 of the lobes 126 cooperativelydefine the absorbent pad 120 as a generally cylindrical pad assembly. Inuse, as seen in FIG. 9A, an arced segment of the cylindrical padassembly is brought into contact with the top face of one of the belts,to define a contact face of the absorbent pad. Although disclosed as agenerally cylindrically shaped absorbent pad 120, the absorbent material128 can take other forms. For example, the absorbent material can be astatic pad (see, e.g., FIG. 12) or could be disposed as a belt (endlessor running end to end) which can have an arced portion thereof broughtinto contact with the top face of the belt to be cleaned.

The absorbent material is flexible, and may be formed from a nonwovenmaterial, a woven material, a knit material, or combinations thereof.Suitable materials include polyethylene, polypropylene, polyolefins,polyesters and nylons. In one embodiment, the absorbent material hascertain desired absorbency characteristics, such as being oleophilic,hydrophilic, or combinations thereof. The absorbent material must alsobe softer than the belt face against which it is engaged, so that thebelt face is not scratched or otherwise abraded during the cleaningprocess. Further, the absorbent material should be nonshedding of fibersso that it does not itself contaminate the belt with debris (andlikewise does not contaminate articles conveyed by the belt, asignificant concern when the articles are food items). In oneembodiment, a scrim is disposed between the absorbent material and topface of its respective belt. In addition, it is important that theabsorbent material have a melt temperature higher than the possibletemperature of the belt. In one embodiment, the absorbent material has amelt temperature higher than 350° F. (177° C.), preferably higher than400° F. (204° C.), and more preferably higher than 450° F. (232° C.).

The absorbent pad 120 is shown in FIG. 1 in contact with the first belt122 for cleaning. A similar absorbent pad 130 is shown in FIG. 1, incontact with the second belt 24. The absorbent pads 120 and 130 aregenerally identical, although oriented for mirror image operation withrespect to their respective belts 22 and 24.

In one embodiment, the absorbent pad 120 is rotated about its axis 124to engage different portions thereof (as its contact face) with itsrespective belt (see, e.g., arrows 132 in FIG. 1). Thus, a clean portionof the outer cylindrical surface of the absorbent pad 120 can be indexedinto position to engage the belt for belt cleaning. The cylindricallyshaped absorbent pad 128 is not rotated to move its outer surface as thesame rate as its belt, but may be indexed periodically (either manuallyor by a motor or other mechanized means). Once the cylindrically shapedabsorbent pad 128 has been completely indexed through an entire rotationabout its axis 124, or is otherwise deemed to be fully saturated withliquid, it is replaced with a fresh absorbent pad.

FIGS. 8, 9 and 9A illustrate the absorbent pad 120 borne by a padhousing 136, thereby defining a pad cartridge 137. The housing 136 hasan enclosure defined by a cylindrical sidewall 138 and opposed endcaps139, with a laterally disposed window 140 in the sidewall 138 forexposure of a portion of the absorbent pad 120. As best seen in FIG. 9A,the window 140 is aligned to expose one or more lobes 126 of theabsorbent material 128 of the absorbent pad 120. In one embodiment,exposed lobes 126 a, 126 b and 126 c are in engagement with the top face34 of the belt 22 as it moves past the absorbent material 120. Indexingthe cylindrically shaped absorbent material 128 about its axis 124 (indirection of arrows 132) will bring the next lobe 126 d into contactwith the belt 22, while allowing lobe 126 a (now fully saturated withliquid) to be moved out of engagement with the belt. Those lobes incontact with the top face of the belt deform to increase the surfacearea of absorbent material in contact with the belt face and “wipe” thebelt face with absorbent material.

The absorbent pad 120 (or if in cartridge form, the cartridge 138), issupported by suitable structure (not shown) relative to its respectivebelt. The absorbent pad 120 is removable and replaceable, so that oncefully saturated with liquid, a fresh pad can be substituted for thesoiled one. The pad may be removable from adjacent the belt, from itshousing if one is provided, or it may be replaced in cartridge form(i.e., the pad and housing are removed and replaced together).

As illustrated in FIG. 9, a motor 150 may be rotatably coupled bysuitable means to the core 122 of the absorbent pad 120, for rotationthereof relative to the housing 136. Suitable bearings 152 may beprovided to facilitate such rotation. The motor can thus be activatedperiodically to rotate the absorbent pad 120 and sequentially presentfresh absorbent material to the belt. In another embodiment, the core isformed as a hollow tube 153 which is perforated (as at 154). The hollowtube 153 is sealed at one end, while at its other end it is coupled to aliquid evacuation system 155 having a pump 156 and liquid collector 158.Thus, absorption of liquid from the belt is aided by drawing a vacuumthrough the absorbent material to draw liquid from its outer edges tothe core (a hollow tube) and then out of the core to be collected.Alternatively, removal of the liquid from the core is accomplished viamechanical means such as a screw auger, piston drive or other fluidconveyance mechanism, alone or in combination with a vacuum draw. Inaddition, the axis of the core can be tilted relative to horizontal toaid in liquid drainage toward its lower end, and removal therefrom.

In one embodiment, means are provided for sensing when the absorbent padis fully saturated with liquid,; and thus needs removal for cleaning orreplacement. Such sensing means may simply be a timer based upon usage,indicating a presumed degree of liquid saturation over time ofoperation, a sensor based on linear exposure of the belt to theabsorbent material, or a weight based sensor, detecting the change inweight of the absorbent pad as it becomes saturated with liquid. Inanother embodiment, the sensor may be an optical sensor 160 mounted, forexample, on the core. The optical sensor 160 may be aligned to bedirected radially outwardly from the core, to detect the change inopacity of the absorbent material as it becomes saturated with liquid(the absorbent material becomes less opaque as it becomes moresaturated). The sensor may also be used to detect partial saturation,and thus provide a signal (e.g., to the motor 15) to facilitate indexedadvance of the absorbent material relative to the belt.

FIG. 10 illustrates an alternative absorbent pad design 164. Thealternate pad design 164 is aligned to present a single lateral padsurface 166 of absorbent material 168 to a passing belt. The absorbentpad 164 is not indexable relative to the belt, and once the absorbentmaterial 168 is fully saturated with liquid, the absorbent pad 164 issimply replaced, or removed for cleaning and reuse. The pad surface 166is positioned by suitable structure (not shown) relative to the face ofits respective belt to be engaged so that it deflects against it topresent the largest, possible surface area, and thereby “wipe” the faceof the belt while absorbing liquids therefrom.

As illustrated by phantom absorbent pads 162 in FIG. 1, absorbentmaterial may be disposed to wipe against the bottom faces 36 and 40 ofthe belts 22 and 24, thereby removing by absorption any residual liquidthereon (that may have migrated to the bottom face during processingfrom the top face of the belt).

FIG. 11 illustrates the article conveying system 20 including anotheralternative absorbent pad design, which comprises an absorbent pad unit320 located along the top face 34 of belt 22. Absorbent pad unit 320 maybe located almost anywhere along belt 22, with the particular locationchosen as a matter of convenience and available space. In oneembodiment, for example, the absorbent pad unit 320 is attached to thebelt wiping blade assembly 90. In a preferred embodiment, the absorbentpad unit 320 is located along an outer vertical segment of the belt 22.It is further desirable to locate the absorbent pad unit 320 at thehottest possible location so that grease on the belt 22 is at its mostsoluble, for example, by locating the absorbent pad unit 320 close tothe roller 26 at the bottom of the outer vertical segment of the belt22. A mirror image absorbent pad unit 322 is located along the belt 24,in the same manner as for absorbent pad unit 320.

As seen in FIG. 12, an alternative pad unit 320 comprises a plurality ofindividual sheets 326 of liquid absorbent material 328 laterallydisposed in a stack. In one embodiment, the sheets are horizontallydisposed and the stack is vertically disposed. The individual sheets 326are bonded together along first edges 329 of each of the sheets 326,along a first face 332 of absorbent pad unit 320. A second contact face340 is defined by the opposite second edges 333 of the sheets 326. Inoperation, the contact face 340 engages the top face 34 of the belt 22.In one embodiment, the absorbent pad unit 320 is not indexable relativeto the belt, and once the absorbent material 328 is fully saturated withliquid from the belt 22, the absorbent pad unit 320 is simply replaced,or removed for cleaning and reuse.

The absorbent material 328 may be any of the types described withrespect to the previous embodiments. In a preferred embodiment, theabsorbent material 328 is spunbond polyethylene terephthalate (PET). Theindividual sheets 326 are also generally about 20-30 mils (0.5080-0.7620mm) thick. In a preferred embodiment, each sheet 326 is about 22 mils(0.5588 mm) thick.

In one embodiment, the absorbent pad unit 320 has a height H of 0.5inches (1.27 cm), a length L of 7.75 inches (19.685 cm), and a width Wof 1.0 inches (2.54 cm). In another embodiment, the absorbent pad unit320 has a height H of 0.5 inches (1.27 cm), a length L of 6.75 inches(17.145 cm), and a width W of 1.0 inches (2.54 cm). In order to achievea height H of 0.5 inches (1.1.27 cm), when individual sheets 326 are of22 mils (0.5588 mm) thickness, the absorbent pad unit 320 typicallycomprises about 38-40 individual sheets 326.

FIG. 13 illustrates the absorbent pad unit 320 positioned relative thebelt 22. The absorbent pad unit 320 is typically positionedperpendicular to the belt 22. The absorbent pad unit 320 is positionedsuch that one or more individual sheets 326 deflect against (“wipe”) thetop face 34 of the belt 22. The absorbent pad unit 320 is loaded intension relative to the top face 34 of the belt 22, as the contact face340 of the absorbent pad unit 320 maintains intimate contact with thetop face 34 of the belt 22, generally causing two or more of theindividual sheets 326 to fan apart at or near the contact face 340. Forexample, the absorbent pad unit 320 may have one-sixteenth inch (0.15875cm) deflection spacing, meaning the contact face 340 would extendone-sixteenth of an inch (0.15875 cm) beyond the top surface 34 of thebelt 22 if not for deflection of the sheets 326 of the absorbent padunit 320 caused by contact with the top surface 34 of the belt 22.

The first edges 329 of the individual sheets 326 may be bonded togetherusing any suitable technique, including: the use of adhesives; potting;thermal bonding such as roll, plate, wire, ultrasonic, induction orother thermal bonding techniques; or mechanically clamping or retainingthe sheets 326 together. Bonding the individual sheets 326 at the firstface 332 prevents individual sheets 326 from separating from theabsorbent pad unit 320 as the sheets 326 fan apart near the secondcontact face 340.

In one embodiment, means are provided for sensing when the absorbent padunit 320 is fully saturated with liquid, and thus needs removal forcleaning or replacement. Such sensing means may simply be a timer basedupon time of usage, indicating a presumed degree of liquid saturationover time of operation, a sensor based on linear exposure of the belt 22to the absorbent material 328, or a weight based sensor, detecting thechange in weight of the absorbent pad 320 as it becomes saturated withliquid. In another embodiment, the sensor may be an optical sensor (notshown) mounted, for example, adjacent the pad 320. The optical sensormay be configured to detect the change in opacity of the absorbentmaterial (as it becomes more saturated).

As illustrated by phantom absorbent pad units 344 in FIG. 11, anabsorbent material pad unit, comprising individual sheets of absorbentmaterial, may be disposed to engage (i.e., wipe against) the bottomfaces 36 and 40 of the belts 22 and 24. Absorbent pads may be arrangednearly anywhere along the bottom faces 36 and 40 of the belts 22 and 24,with the particular location chosen as a matter of convenience andavailable space. Typically, absorbent pad units 344 are located nearabsorbent pad units 320 and 322, respectively. In further embodiments,performance may be enhanced when support is provided to the belts 22 and24 directly opposite the absorbent pad units 320 and 322, respectively,such as where absorbent pad units 344 are positioned directly oppositeabsorbent pad units 320 and 322 on either sides of the respective belts22 and 24.

In order to increase the amount of absorbent material exposed to thebelt face, the absorbent material may be tilted relative to the belttravel direction (see, e.g., FIG. 14). Accordingly, the absorbentmaterial (whether in the form 128 shown in FIGS. 1 and 7-9A, in the form168 shown in FIG. 10, in the form 320 shown in FIGS. 11-13, or in someother functionally equivalent form) is disposed as at 178 in FIG. 14,relative to a belt such as belt 24. The direction of belt travel isindicated by arrow 179. As seen, absorbent material 178 is tiltedrelative to the belt 24 (i.e., tilted relative to horizontal). Thus, theabsorbent material can be longer than the lateral width of the belt, andthereby present a greater surface area to the belt face which passes bythe absorbent material.

Belt Edge Seals

As noted above, it is undesirable that liquid and/or debris migrate fromthe top face of a belt to its edges or to its bottom face. The inventivecleaning assembly thus includes edge seals for placement between theopposed belts along the article transport path. The edge seals serve asa physical barrier to contain liquids and debris from reaching thelateral side edges of the belts. As seen in FIG. 1A, the first belt 22has lateral side edges 180 and 182, while the second belt 24, as shownin FIG. 2, has lateral side edges 64 and 66. Along the article transportpath 45, the opposed top faces 34 and 38 of the belts 22 and 24 arespaced apart by a distance “d”. A first resilient edge seal 190 isdisposed across the space “d” adjacent the lateral side edges 180 and64, while a second resilient edge seal 192 is disposed adjacent opposedlateral side edges 182 and 66.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

1. A cleaning assembly for removing liquids from an endless conveyorbelt, the assembly comprising: a plurality of laterally extending liquidabsorbent material sheets disposed adjacent the belt, with the sheetscollectively defining a contact face that is engageable with the beltfor wiping liquids and solids from the belt.
 2. The cleaning assembly ofclaim 1, wherein the plurality of sheets are substantially verticallyaligned in a stack.
 3. The cleaning assembly of claim 2, wherein theplurality of sheets are affixed together along a first face of the stackthat is disposed opposite the contact face.
 4. The cleaning assembly ofclaim 1, wherein the absorbent material is selected from the groupconsisting of a nonwoven material, a woven material, and a knitmaterial, or combinations thereof.
 5. The cleaning assembly of claim 1,wherein the absorbent material has a melt temperature greater than 350°F. (177° C.).
 6. The cleaning assembly of claim 1, and furthercomprising: a sensor for generating a signal indicative of the degree ofliquid saturation of the absorbent material.
 7. The cleaning assembly ofclaim 6, wherein the sensor detects the change in weight of theabsorbent material over time.
 8. The cleaning assembly of claim 6,wherein the sensor detects the change in opacity of the absorbentmaterial over time.
 9. The cleaning assembly of claim 1, wherein theabsorbent material has one or more of the following characteristics:oleophilic, hydrophilic, or a combination thereof.
 10. The cleaningassembly of claim 1, wherein the absorbent material is spunbond PET. 11.The cleaning assembly of claim 1, wherein the sheets are disposedsubstantially perpendicular to the belt, and disposed relative the beltat a distance such that at least one of the individual sheets todeflects due to contact with the belt.
 12. A cleaning assembly forremoving liquids from an endless conveyor belt, the assembly comprising:a liquid absorbent material unit disposed adjacent the belt, wherein theabsorbent material unit comprises a stack of laterally extending sheetsof absorbent material affixed together at first edges of each of thesheets, wherein at opposite second edges the sheets collectively definea contact face on the absorbent material unit that is engageable withthe belt for wiping liquids and solids from the belt, and wherein atleast one of the sheets deflects when engaged with the belt.
 13. Thecleaning assembly of claim 12, wherein the absorbent material isselected from the group consisting of a nonwoven material, a wovenmaterial, and a knit material, or combinations thereof.
 14. The cleaningassembly of claim 12, wherein the absorbent material has a melttemperature greater than 350° F. (177° C.).
 15. The cleaning assembly ofclaim 12, and further comprising: a sensor for generating a signalindicative of the degree of liquid saturation of the absorbent material.16. The cleaning assembly of claim 15, wherein the sensor detects thechange in weight of the absorbent material over time.
 17. The cleaningassembly of claim 15, wherein the sensor detects the change in opacityof the absorbent material over time.
 18. The cleaning assembly of claim12, wherein the absorbent material has one or more of the followingcharacteristics: oleophilic, hydrophilic, or a combination thereof. 19.The cleaning assembly of claim 12, wherein the absorbent material isspunbond PET.
 20. A method for removing liquids from an endless conveyorbelt, the method comprising: advancing the belt; and engaging the beltwith a contact face of a liquid absorbent material unit disposedadjacent the belt, wherein the absorbent material unit comprises a stackof laterally extending sheets of absorbent material affixed together atfirst edges of each of the sheets, wherein at opposite second edges thesheets collectively define the contact face of the absorbent materialunit, and wherein at least one of the sheets deflects when engaged withthe belt.
 21. The method of claim 20, and further comprising:periodically replacing the liquid absorbent unit relative to the belt.